Water Quality in Longmont, CO: 19 Violations - Grade N/A
8 water systems · 3 directly mapped ZIP records
Available EPA records report 19 violations across 3 directly mapped ZIP records with known counts for Longmont. This is compliance evidence, not a property-level tap-water verdict.
Data: EPA Safe Drinking Water Information System (SDWIS)
Water Quality by ZIP Code in Longmont
This table shows typed EPA water evidence only. Missing violation counts are displayed as N/A, not zero.
| ZIP Code | Violations | Health | |
|---|---|---|---|
| 80504 | 17 | 0 | View report → |
| 80503 | 4 | 0 | View report → |
| 80501 | 2 | 0 | View report → |
Water Quality Overview
Longmont, Colorado has directly mapped EPA water-system data for 3 ZIP codes. This page reports typed compliance facts and does not relabel the multi-source Home Safety Score as a drinking-water grade.
The available EPA records report 19 violations (all classified as monitoring/reporting type in the available record) across 3 directly mapped ZIP records with reported counts.
Lead Levels
The average 90th percentile lead level across Longmont water systems is 0.0045 mg/L - within EPA limits. No exceedances appear among the 3 ZIP records with known lead status.
With 43% of homes built before 1986, Longmont has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Water Systems Serving Longmont
Longmont is served by 8 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 141,102 people across 4 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 23 enforcement actions against water systems serving Longmont. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Longmont
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels and violation history
Request your CCR - your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test - certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration - NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories - monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Longmont Water Systems
The following contaminants have been detected or caused violations across Longmont's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 5 | 3 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 5 | 3 | No |
| E. coli | Microbiological | N/A | 4 | 2 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 3 | 1 | No |
| Fecal Coliform | Microbiological | N/A | 2 | 2 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 2 | 1 | No |
| Revised Total Coliform Rule | Microbiological | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 17 enforcement actions against water systems serving Longmont. Recent actions:
| Date | Action Type |
|---|---|
| 2024-12-04 | State Order Extension |
| 2024-11-05 | State Informal Action |
| 2024-11-05 | State Informal Enforcement |
| 2024-10-24 | State Informal Action |
| 2024-10-24 | State Informal Enforcement |
| 2023-03-24 | State Informal Action |
| 2022-10-24 | State Order Extension |
| 2022-10-10 | State Informal Action |
| 2022-10-10 | State Informal Enforcement |
| 2022-08-03 | State Order Extension |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2024-12-04.
Longmont vs. Nearby Colorado Cities
How Longmont's water quality compares to similar cities in Colorado:
| City | Direct EPA ZIPs | Violations | Systems | Population |
|---|---|---|---|---|
| Longmont | 3 | 19 | 8 | 141,102 |
| Arvada | 5 | 9 | 8 | 138,109 |
| Boulder | 6 | 110 | 14 | 129,202 |
| Pueblo | 7 | 123 | 5 | 161,607 |
Water Quality by ZIP Code in Longmont
EPA coverage and recorded violations can differ across Longmont's ZIP codes. Missing counts are shown as unavailable, not zero:
Common Questions About Longmont Water
These are the most common questions residents search for about water quality in Longmont, Colorado:
Is Longmont water hard or soft? Water hardness varies by source. Longmont's 8 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Longmont tap water? City-level EPA records cannot determine safety at a specific tap. No health-based violations are recorded across 3 directly mapped ZIP records with known counts, but this is not a property-level safety guarantee.
What is the best water filter for Longmont? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Longmont vs. Colorado Average
Understanding how Longmont compares to the broader Colorado average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below - water quality can vary significantly even within Longmont.
ZIP Codes in Longmont
Longmont spans 4 ZIP codes. EPA water-system coverage is available for 3 directly mapped ZIP codes. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Source reporting periods vary. See each cited source for its publication schedule.